Food Additives Explained: What Every Label Ingredient Actually Does

Pick up any packaged food and read the ingredient list. Somewhere in that list, past the flour and sugar and salt, you’ll hit something like “calcium propionate” or “soy lecithin” or “sodium benzoate.”

Those are food additives. And most people have no idea what they’re actually doing in the food.

That’s worth fixing. Not because you need to be afraid of them, but because understanding what an ingredient does and why it’s there is just useful knowledge. It helps you read labels with actual comprehension instead of vague unease.

What a Food Additive Actually Is

A food additive is any substance added to food that wasn’t originally in the food itself. That’s a broad definition. It includes obvious things like artificial preservatives and artificial colors. It also includes things you’d probably never think of as additives: vitamins added to enrich flour, iodine added to salt, and the tiny amounts of processing aids used during manufacturing.

The FDA splits these into two big categories.

Direct additives are intentionally added to food to do a specific job. Preservatives, emulsifiers, thickeners, sweeteners, and colors are all direct additives. The manufacturer put them in on purpose.

Indirect additives get into food as a side effect of packaging, processing equipment, or storage. The plasticizers from certain food packaging materials are an example. Most people don’t think about these, but regulators do.

This article focuses on direct additives, because those are the ones you see on labels.

The 5 Main Categories

Food additives show up in five main functional groups. Most additives you’ll see on labels fit into one of these.

Preservatives slow or prevent spoilage. They work by inhibiting microbial growth (bacteria, mold, yeast) or by preventing oxidation of fats and pigments. Sodium benzoate, sodium nitrite, BHA, BHT, and TBHQ all fall here. Without preservatives, most shelf-stable packaged foods would spoil in days.

Emulsifiers and stabilizers keep ingredients mixed that would otherwise separate. Oil and water don’t mix naturally. Emulsifiers have a molecular structure that bridges both, holding the mixture stable. Soy lecithin in chocolate, carrageenan in dairy products, and mono- and diglycerides in bread all work this way. Without them, your salad dressing would be a separated mess within minutes of shaking.

Thickeners change the texture of food by absorbing water and forming gels or viscous solutions. Xanthan gum, guar gum, pectin, and modified food starch are common examples. They give sauces their body and prevent ingredients from settling to the bottom of a bottle.

Sweeteners add sweetness without sugar, or add sweetness more efficiently than sugar. This category splits into nutritive sweeteners (like high-fructose corn syrup, which still provides calories) and non-nutritive sweeteners (like sucralose and aspartame, which provide very few or no calories).

Colors and flavors change or enhance how food looks and tastes. This is the largest category by count. Artificial colors like Red 40 and Yellow 5 replace pigments that would otherwise fade during processing. Natural flavors (a legally defined but surprisingly broad term) come from plant or animal sources. Artificial flavors are synthesized compounds, sometimes identical to natural ones, sometimes novel.

How Additives Get Approved in the US

This is where things get more complicated, and where a lot of public confusion lives.

The FDA has two main pathways for allowing a substance in food.

The food additive petition process is the stricter one. A manufacturer submits a petition with safety data. FDA reviews it. If approved, the additive gets a specific authorization with defined use conditions (what foods, at what maximum levels). This is what most people imagine when they think of “FDA approved.”

The GRAS pathway is different. GRAS stands for Generally Recognized as Safe. Under this pathway, a substance can be used in food if there is broad scientific consensus that it’s safe, based on either a long history of safe use (pre-1958) or peer-reviewed scientific evidence. The controversial part: companies can make their own GRAS determinations without telling the FDA at all. They can then use those substances in food without going through a formal petition process.

This self-determination pathway has drawn significant criticism. A 2013 analysis by Neltner et al. found that the vast majority of GRAS determinations were conducted by panels with financial ties to the food industry. The FDA has acknowledged this as a systemic gap.

A key distinction worth understanding: FDA-approved means the FDA reviewed the data and issued a specific authorization. GRAS means the substance is considered safe by scientific consensus, but that determination may or may not have been reviewed by the FDA directly. Both allow a substance to be used in food. Neither is a permanent guarantee of safety forever.

The JECFA and EFSA Factor

FDA isn’t the only authority that matters here. Two international bodies do independent evaluations that often inform US policy and definitely influence what’s permitted in other countries.

JECFA (Joint FAO/WHO Expert Committee on Food Additives) is a UN-level scientific committee that establishes acceptable daily intakes (ADIs) for food additives globally. When JECFA sets an ADI, it’s typically based on animal studies, with a 100-fold safety margin built in. An ADI of 5 mg/kg body weight means the highest dose that caused no observable effect in animals, divided by 100.

EFSA (European Food Safety Authority) evaluates additives for EU approval. The EU tends to act earlier than the US when evidence of concern emerges. Several additives still permitted in the US have been banned or restricted in the EU (potassium bromate, titanium dioxide, certain food dyes, BVO).

This divergence isn’t because EU regulators are smarter or more careful. It often reflects different regulatory philosophies. The EU applies more of a precautionary principle: when in doubt, restrict. The US tends to require stronger evidence of harm before restricting. Neither approach is automatically right.

How to Read an Ingredient Label

The ingredient list on US food labels follows specific rules. Ingredients are listed in descending order by weight. The first ingredient is the most abundant; the last ingredient is the smallest amount.

For additives specifically, a few label conventions matter.

Common names vs. chemical names. The FDA allows manufacturers to use common names when they exist. “Vitamin C” instead of “ascorbic acid.” “Sugar” instead of “sucrose.” But for most additives, the chemical or regulatory name is what appears. This is one reason labels look intimidating. “Disodium inosinate” sounds alarming. It’s a flavor enhancer found naturally in meat and fish.

Natural flavors. This term means flavoring substances derived from plant or animal sources. It doesn’t tell you what the substance is, just its origin. Two products with “natural flavors” can contain completely different compounds.

E-numbers. You won’t see E-numbers on US labels. Those are the EU’s numbering system. E300 is vitamin C. E621 is MSG. If you’re reading a European product label, E-numbers tell you the substance has been approved by EFSA. They don’t appear on American packaging.

Natural vs. Synthetic: A Distinction That Doesn’t Tell You Much

This is worth stating clearly because it comes up constantly.

Whether a food additive is derived from nature or synthesized in a laboratory tells you almost nothing about whether it’s safe. Safety depends on the specific molecule, the dose, how your body processes it, and cumulative exposure over time.

Arsenic is natural. Botulinum toxin is natural. Certain mushroom toxins are natural.

Ascorbic acid is often synthesized. Citric acid is mostly produced by fungal fermentation of corn syrup in an industrial setting. Vanillin (the main flavor compound in vanilla) is overwhelmingly synthetic, because natural vanilla extraction can’t meet global demand.

The molecule is what matters, not its origin story. “Natural” and “synthetic” are marketing concepts masquerading as safety information.

What’s Under Review Right Now

The food additive landscape (in the regulatory sense) is more active right now than it’s been in years.

The MAHA (Make America Healthy Again) movement, gaining momentum in 2025-26, has pushed FDA to prioritize re-evaluating a list of additives that have long safety records but have never been subject to modern toxicological review. Many of these were approved under older, less stringent standards or grandfathered in before modern testing requirements existed.

FDA added several additives to its priority review list in 2025, including BHA, Red 40 and other certified color additives, and several other substances.

Meanwhile, the California Food Safety Act (AB 418, signed 2023) created a state-level precedent by banning four additives in food sold in California: potassium bromate, brominated vegetable oil, propylparaben, and red dye No. 3. BVO has since been banned federally. Red 3 was banned by FDA in January 2025. The California law takes effect January 1, 2027 for the remaining two.

This doesn’t mean these substances are proven dangerous. It means the evidence is uncertain enough that multiple regulators think a harder look is warranted. That’s a meaningful signal.

The Dose Always Matters

Every toxicologist’s first principle: the dose makes the poison. Water causes hyponatremia at extreme intake. Acetaminophen causes liver failure at high doses. Oxygen at high partial pressures causes toxicity in divers.

For food additives, the ADI (acceptable daily intake) concept exists precisely to account for this. An ADI represents the amount you could consume every day for your entire life without a meaningful risk of harm, with a large safety margin already built in.

When animal studies show cancer at a certain dose, regulators don’t automatically conclude the same thing happens in humans. They look at the dose used in the study relative to realistic human dietary exposure, the mechanism of harm, whether it applies to human biology, and the strength of evidence from multiple studies.

This process isn’t perfect. Some additives get re-evaluated and found wanting decades after initial approval. But the systematic application of dose-response principles means that reading a headline about “X chemical causes cancer in rats” tells you almost nothing without the dose context.

A Note on Cumulative Exposure

One genuine gap in the current regulatory framework: additives are generally approved one at a time, based on individual safety assessments. But people eat foods containing dozens of different additives simultaneously, day after day, year after year.

Cumulative and combined exposure is much harder to study than single-substance exposure. The regulatory community knows this is a gap. It’s one reason some researchers argue for more caution than the current system requires.

This doesn’t mean every additive combination is dangerous. It means the science of multi-substance interaction is genuinely less developed than single-substance safety science.

The pages linked below cover individual additives in detail, including what the evidence actually shows and what verdict regulators have reached. Start with any additive you’ve seen on a label and wondered about.